Problem: Simplify the following expression: $a = \dfrac{3x + 7}{6x} \times \dfrac{1}{7}$
Explanation: When multiplying fractions, we multiply the numerators and the denominators. $a = \dfrac{(3x + 7) \times 1} {(6x) \times 7}$ $a = \dfrac{3x + 7}{42x}$